Armature for dynamo-electric machines



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A. W. MESTON.

ARMATURE FOR DYNAMO ELECTRIC MACHINES. No. 387,432. PatentedAug. '7,1888.

N. PETERS, Phuw-Lmw npher, Washington, D c.

5 Sheets-Sheet 2.

(No Model.)

A. W. M'ESTON.

ARMATURE FOR DYNAMO ELECTRIC MACHINES No. 387,432.

Patented Aug. '7, 1888.

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A. W. MESTON.

ARMATURE FOR DYNAMO ELECTRIC MACHINES. No. 387,432.

Patented Aug. 7, 1888.

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(No Model.)

A. W. MESTON.

ARMATURE FOR DYNAMO ELECTRIC MACHINES.

Patented Aug. '7, 1888.

amen/ b8 Jaw! 2k 274% @51 after/mai l vi'tneooao N, Ptrzns,Pholo-Lilhngnpher. Washington. 1:v c.

(No Model.)

A. W. MESTON.

ARMATURE FOR DYNAMO'ELEGTRIG MACHINES. No. 887,432.

PatentedAug. 7, 1888.

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PATENT OF ST. LOUIS, MISSOURI.

ARMATURE FO? DYNAMO=ELECTRiO WlACrilNiS.

SPECIFICATION forming part of Letters Patent No. 387,4:82, dated Augusti, 1888.

.87. Serial No. 257, 940.

(No model.)

To aZZ whom it may concern:

Be it known that I, ALEXANDER W. Mns- TON, a citizen of the UnitedStates of America, residing at St. Louis, in the State of Missouri,haveinvented certain new and useful Improvements in Armatures forDynamo-Electric Machines; and I hereby declare the following to be afull, clear, and exact description of the same, reference being made tothe accompanying drawings, wherein like letters refer to like partsthroughout the several views.

This invention relates to improvements in that class of armatures knownas ring-armatures, and applies particularly to the Hat or Pacinotti typeof such armatures.

The objects of the invention are, first, to provide means in fiatring-armatures whereby sections thereof, comprising one or more coilswhich have become damaged, may be readily replaced by duplicate andperfect sections, and to have such sections of such dimensions and formas will allow of their being revolved in an ordinary lathe orothersuitable machine for the purpose of winding the armature-coils,doing away with theslow and laborious method of hand-winding, which theform of the ordinary ringarmature necessitates; second, improvement inthe construction of laminated flat ring-armatures, whereby, withoutmaterially affecting their strength and without niaterially increasingthe magnetic resistance of the core, sections or portions of the ringhaving one or more coils wound thereon can he readilydetaohed and takenout and duplicate sections inserted; third, improvement in theconstruction of laminated sectional ring-armatures, wherebyinterchangeability of parts is attained; fourth, to combine with theforegoing features a perfect insulation of the laininze composing sucharmatures and of the sections from each other without materiallyaffecting the magnetic continuity of the core; fifth, to combine inlaminated sectional ring-armature strength, rigidity, and accuracy ofstructure and cheapness of manufacture; sixth, to provide for theventilation of such armatures, and, seventh, improvement in the mannerof attaching such armatures to the spiders on which they are mounted,providing at the same time for the insulation of the armature from thespider.

Laminated armatures of the flat ring or Pacinotti type have hithertousually been so constructed as to form a continuous ring, upon which thecoils are wound. course precludes all possibility of winding sucharmatures otherwise than by hand, literally winding the wire around thecore, which is a slow, tedious, and expensive operation. It thus becomesnecessary, should any accident occur to one or more coils, to abandonthe use of the entire armature until these coils can be laboriouslyunwound and rewound in the manner stated, which in large machines is anundertaking requiring several days to perform, during which time themachine is useless. Such a loss of time is generally a very seriousinconvenience to those op rating dynainos or motors, and often causesgrave doubts to be cast upon the reliability of this class of machinery.It is therefore chiefly with the object of facilitating and cheapeningtheir repair and manufacture that I have devised the arniatures hereindescribed, and also with the object of improving the construction of sectional laminated ringarmaturcs, as regards efficiency, cost, strength,stiffness, and accuracy. The methods which I employ to attain theseobjects are illustrated in the accompanying drawings, wherein Figure lis a side view of an entire armature without the wire. Fig. 2 is an edgeview of the same. Fig. 3 is a sectional view of the same through theline A B in Fig. 1. Fig. a is alike sectional view showing a modifiedform of spiders. Fig. 5 is a side view of a detached section with theradial polepiece attached.

Fig. 6 is an end view of the section shown in Fig. 5. Fig. 7 is a topview or plan of same. Figs. 8 and 9 are side and edge views of theradial pole-piece P. Fig. 1) is a side elevation of a detached section,in which provision is made for ventilating the interior of the core, andin which the wire coils are shown in section for the purpose ofindicating how the coils are wound on the section. Fig. 11 is asectional view of the same through the line A B in Fig. 10, the wirecoil omitted. Fig. 12 is a top view or plan of the same. Fig. 13 is adetached sectional. view of the bent plate )I through the line A B inFig. 10. Fig. it is a side view of a modified form of section. Fig.

Their form of ICO 15 is a sectional view of same through line C D inFig. 14. Fig. 16 is a top or plan View of same.

The section shown in Figs. 5, 6, and 7 has a solid core composed ofalternate long and short layers or plates of sheet-iron fastenedtogether by a suitable number of rivets, as r 7" 1'. These plates soarranged form at each end of the section alternate tongues a a a, &c.,and recesses b b Z), &c. The short plates leave recesses, into which thetongues formed by the projecting plates of the adjoining section fit,bringing the holes h h in the interjacent tongues ofthe two sectionsopposite each other. A polepiece, P, is then placed on each side,fittinginto the radial recesses formed between the coils. The whole isthen fastened together by countersunk headed bolts passingth rough oneof the pole-pieces, through the holes h h in the interjacent tongues ofboth sections, and screwed into the pole-piece on the oppposite side.The lug of the pole-piece, which projects inward, is then bolted to thespider, as shown in Figs. 1, 3, and 4. The remaining sections aremounted and fastened together in the same manner until the ring iscompleted. The complete ring mounted on the shaft.- is shown in Figs. 1,2, 3, and 4. The two outside plates of each section are of a suitableshape, and are bent up at the ends to a right angle to form thefiangesff, between which the armature-coils s are wound, and which keepthe coils in position when the section is detached from the armature andconfine and form the coil wire during the process of winding. Theseflanges also serve as a guide when slippping the coil into its place andprotect the insulation of the coil from injury, and aid materiallyinstiffening the armature by fitting against the sides of the insertedpole-pieces. The coils s are insulated from the core in the usual way.

The plates composing the sections may be insulated from one another byany suitable material to prevent the generation and flow of Foucaultcurrents. To make the insulation of these plates perfect, the rivets bywhich they are held together, and the bolts passing through thepole-pieces and holding the sections together, may be insulated from thecore by means of vulcanized fiber or other non-conducting bushings, as cc 0, 8:0. The polepieces may be insulated from the spider by means ofnon-conducting washers, as shown by d din Figs. 3 and 4, and byinsulating the bolts with bushings, as e e in the same figures. Thespider should be made of brass, gun-metal, bronze, or other nonmagneticmaterial, that it may not form a conductor by which the magnetic linesof force can escape across from one pole of the field to the otherwithout being traversed by the wire of the armature-coils.

The pole-piece 1? (shown detached in Figs. 8 and 9) I prefer to make ofseparate plates of soft sheet-iron, as indicated in the drawings, whichmay be insulated and riveted in the same manner as the sections. Bydoing this and using dies to stamp out the sheets and holes perfectuniformity of shape and also in the position of the holes is attained.This could not be done if they were cast or forged in one piece withoutmuch skilled and correct labor. A better quality of iron, more perfectlyannealed, can also be secured by this means.

In thesection shown in Figs.10, 11, and 12 provision is made forventilating the interior of the core. It is constructed in the samegeneral way as the solid section,with the exception thatseveral of theplatespreferably several near the out-sideofthecore-areomittedandtheir-places occupied by the detached washers 'w w w or other piecessuitably shaped to allow a free circulation of air, as shown in thedrawings. In this construction the outside plates, which are bent up toform the flanges f f, are cut somewhat narrower than the other sheets ofthe core. This leaves a shallow recess or groove along each corner ofthe core, into which the bent shield-plates M M fit. These plates coverthe edges or" the core, and, being a short distance from said core,leave an airspace, allowing a free circulation of air between said plateand the core and co1nmunieating with the spaces in the interior of thecore kept open by the washers w w 10. When the armature revolves, acurrent of air is set up, flowing in under the shield-plate M, coveringthe inner edge of the core, up through the spaces in the core, and outunder the shield-plate M, covering the outer edge of said core, asindicated by arrows in the drawings.

In the construction of the section illustrated by Figs. 14, 15, and 16the bent shield-plate M is employed, as in Figs. 11, 12, and 13, butmerely for the purpose of covering the sharp edges of the plates of thecore to prevent abrasion of the insulation between them and the wire ofthe coils s. It may, however, be placed some distance from the core, asin Figs. 11,12, and 13, to allow a partial ventilation of the coil.

If as many tongues and recesses as there are plates in the section arenot desired, two or more plates may be used for each tongue and recess.While the joining is not so strong nor so perfect, magneticallyasifevery plate formed a tongue or recess, still, where the core hasconsiderable thickness and is composed of many plates, the strength andmagnetic inti macy would be ample. It will be seen that this method ofinterleaving the plates gives great strength,as the bolt holding thesections together would have to be sheared as many times as there aretongues before the sections could be pulled apart.

The armature may be mounted upon two separate spiders, as shown in Fig.4, instead of one, as shown in Fig. 3. This provides means of adjustmentfor various thicknesses of cores.

The flange shown on the bent shield-plate M, forminga continuation ofthe flangef, may

- or may not be used, as desired.

Neither need the flange f extend farther than the edge of the core.

If the armature is not required for heavy duty, or where high efficiencyis not important, it is not necessary to insulate the laminte of thesections nor to use the method of ventilation herein described; but itis desirable to do so where these conditions do not exist, to preventthe armature from heating, by breaking up the Foucault current-circuitsin the nterior of the core, and also by the cooling influence ofair-currents. I consider that the best method of insulating the laminteis to cover them, either in the sheet or after they have been cut toshape, with a thin coating of some insulating compound, such asJapan,asphaltum, varnish, or other suitable mixture.

I attain several desirable advantages in sectional armatures by theconstruction herein described.

By building the sections up of alternate long and short sheets ofiron,so that the same sheet forms the tongue at both ends, greatstrength and safety, and also accuracy and uniformity of dimensions, aresecured, as the long plates form a continuous ring when joined together,and neither the strength nor the length of the section depends uponthescrews or rivets which hold the plates together. Whereinterchangeability of section is desired,the last-mentioned feature isvery important.

The form and strength of the ring are preserved entirely independent ofthe spider upon which it is mounted, and thejoining of the sections isseparate from and in no way connected with their fastening to thespider. The nonmagnetic spider does not extend into the magnetic core ofthe sections, but is wholly within the internal diameter of said core.

I am aware that sectional armatures have been devised wherein thesections are bolted or otherwise fastened directly to projecting arms orlugs of the non-magnetic spidenwhich extend out into the magnetic coreof the sections for the purpose. These nonanagnctic arms or lugs occupyspace which might otheu wise be filled to advantage with iron anddecrease the magnetic conductivity of the core. This is a gravedisadvantage which I obviate in my construction, as the sectional ringis mounted upon the spider by means of the magnetic pole-piecesextending inward to said spider, which is wholly within the innercircumference of the magnetic ring. In this way I get a maximum amountof iron in the core and pole-pieces, which greatly increases theefficiency of the armature by lowering its magnetic resistance andpreserving throughout the magnetic section of the core. By this methodof mounting I am also enabled to get the greatest possible amount ofwire on the sections, as the necks of the magnetic pole-pieces by whichthe ring is mounted upon the spider emerge from between the coils at theoutside, where by reason of the curved form of the coils there is alwaysan opening, even when the coils are close together at their inner edges.

The most serious fault which has heretofore existed in sectionalarmatures is the imper fectness of the magnetic connection and iuti macyof the sections. None of the armatures of which I have knowledge combinea perfect insulation of the sections from each other, and at the sametime maintain the magnetic coir tinuity of the ring. By making a greatmany laminations in the core, so that the greatest possible number oftongues and recesses is formed, I am enabled to break up the inducedcurrents by insulating thelamiute and the sec tions from one anotherwithout decreasing the magnetic conductivity of the ring, because by sodoing a very large surface of the plates of the adjacent sections isbrought into close proximity, thus almost eliminating the mag neticresistance of the insulation.

I am aware that sectional riug-armatures have heretofore been made, andI have no intention of broadly claiming such a construction. I am notaware, however, of any armaturcs embodyingthe improvements andadvantages possessed by the armature herein de scribed; and,

Having thus fully and clearly explained the objects, construction, andoperation of my invention, I claim and desire to secure by LettersPatent- 1. A flat ring-armature composed of laminated sections, havingone or more coils of wire wound on each section, any of such. sectionsbeing detachable, said sections composed of alternate long and shortplates fitting and joined together by means of the tongues and recessesformed thereby, substantially as and for the purposes specified.

2. A flat ringarmature composed of lami nated sections, the lamina:thereof being insulated from each other, having one or more coils ofwire wound on each section, any of such sections being detachable, saidsections composed of alternate long and short plates, fitting and joinedtogether by means of the tongues and recesses formed thereby,substantially as and for the purposes specified.

A flat ring-armature composed of laminated sections, having one or morecoils of wire wound on each section, any of such sec tions beingdetachable, said sections fitting together by means of tongues andrecesses, in combination with a spider and detachable mag neticpole-pieces, by means of which the armature-ring is mounted on thespider, substantially as and for the purposes specified.

i. A fiat ring-armature composed of laminated sections, the lamintethereof being insulated from each other, having one or more coils ofwire wound on each section, any of such sections being detachable, saidsections fitting and joined together by tongues and recesses, incombination with a spider and detachable magnetic pole-pieces,substantially as and for the purposes specified.

5. A flat ring-armature composed of laminated sections, having one ormore coils ofwire wound on each section, any of the such sections beingdetachable, said sections fitting and joined together by tongues andrecesses, in combination with a spider and detachable magneticpole-pieces, said pole-pieces being insulated from the spider,substantially as and for the purposes specified.

6. A flat ring-armature composed of laminated sections, the lamina:thereof being insulated from each other, having one or more coils ofwire wound on each section, any of such sections being detachable, saidsections fitting and joined together by tongues and recesses, incombination with a spider and detachable magnetic pole pieces, saidpole-pieces being insulated from the spider, substantially as and forthe purposes specified.

7. A flat ring-armature composed of laminated detachable sections havingflanged outer plates, and having one or more coils of wire woundthereon, said sections fitting and joined together by tongues andrecesses, substantially as and for the purposes specified.

8. A fiat ring-armature composed of laminated detachable sections, thelaminae thereof insulated from each other, provided with flanged outerplates, having one or more coils of wire wound thereon, said sectionsfitting and joined together by tongues and recesses, substantially asand for the purposes specified.

9. A flat ring-armature composed of laminated detachable sections,provided with flanged outer plates, and having one or more coils of wirewound thereon, said sections fitting andjoined by tongues and recesses,in combination with a spider and detachable magnetic polepieces, bymeans of which the ring is mounted on the spider, substantially as andfor the purposes specified.

10. A flat ring-armature composed of laminated detachable sections, thelaminae thereof insulated from each other and the outer plates flanged,said sections fitting and joined by tongues and recesses, and having oneor more coils of wire wound thereon, in combination with a spider anddetachable magnetic pole pieces, by means of which the ring is mountedon the spider, substantially as and for the purposes specified.

11. Aflat ring-armature composed of lami nated detachable sections,fitting and joined together by tongues and recesses, having flangedouter plates, one or more coils of wire wound thereon, in combinationwith a spider and detachable magneticpole pieces, by means of which thering is mounted on the spider, said pole-pieces being insulated from thespider, substantially as and for the purposes specified.

12. A flatringarmature composed of lami-- nated detachable sections,joined and fitted together by tongues and recesses, the laminae thereofinsulated from each other, the sections having flanged outer plates andhaving one or more coils of wire wound thereon, in combination with aspider and detachable magnetic pole-pieces, said pole-pieces beinginsulated from the spider, substantially as and for the purposesspecified.

13. In a flat ring-armature, the combination ofdetachablelami natedcoresections, aspider, and detachable laminated pole pieces, by means ofwhich the ring is mounted on the spider, substantially as and for thepurposes specified.

14. A dynamoarmature section composed of laminae, the outer plates ofthe laminte being flanged, and shield-plates which are arranged betweenthe flanged plates and cover the edges of the laminte, substantially asand for the purposes specified.

15. A dynamo-armature section composed of laminae, having its outerplates flanged for the coil, and flanged shields to cover the edges ofthe laminae and complete the coil-flanges, substantially as and for thepurposes specified.

16. The combination, in an armature, of a laminated core, twoindependent or separate spiders, and two independent sets of polepieceswhich connect the respective spiders with opposite sides of thelaminated core, substantially as and for the purposes specified.

17. The combination in an armature, of laminated core-sections, twoindependent or separate spiders, and two independent sets of laminatedpole-pieces which connect the opposite sides of the core-sections withtheir respeetive spiders, substantially as and for the purposesspecified.

In testimony whereof I affix my signature, in presence of two witnesses,this 5th day of December, 1887.

'ALEXANDER XV. MESTON.

Witnesses:

HENRY W. EHLERT, WM. BIORGAN.

